The work proposed will develop spectroscopic techniques for studying biomolecular structure. We will continue the development of UV resonance Raman spectroscopy (UVRRS) as an emerging technique for the study of biomolecular structure and function. We will develop new instrumentation to dramatically improve data quality and further develop new methodologies such as Raman saturation spectroscopy and Raman decoupling spectroscopy to examine biomolecular excited state relaxation. We will continue our development of techniques to examine secondary structure of proteins and peptides. We will apply these results to the study of the structure of angiotensin. We will examine excited states of amides and peptides to determine the nature of the excited state potential function. We will also examine the ground state potential function to determine the barriers between trans and cis peptide isomerization. We will examine electronic communication between the heme molecular orbitals and peripheral groups such as the formyl group in heme a as well as electronic communication between the heme and ligands bound to the iron.